배한용 교수

Abstract Highly enantioselective biomimetic Michael addition reactions of malonic acid half thioesters (MAHTs) to a variety of nitroolefins, affording the optically active γ‐amino acid precursors, were developed by employing the Cinchona ‐based squaramides (up to >99% ee ). Remarkably, this biomimetic process is enantioconvergent, a highly desirable feature of a catalytic asymmetric reaction, whereby E / Z ‐isomers of the nitroolefins afford the same product enantiomer. The synthetic utility

In this study, water was demonstrated to be an exceptionally efficient reaction medium for the noncovalent, hydrogen-bonding-promoted enantioselective Michael addition of malonates to diverse nitroolefins using cinchona-based squaramide catalysts. A significant increase in the reaction rate was observed when the reaction was performed “on water” rather than in the conventional organic solvents, because of the hydrophobic hydration effect. This hydrophobic amplification was significantly dependen

Copycat: A highly enantioselective biomimetic aldol reaction of malonic acid half thioesters with a variety of aldehydes affords optically active β-hydroxy thioesters by employing the cinchona-derived sulfonamide organocatalyst 1. The synthetic utility of this protocol was demonstrated by performing formal syntheses of the antidepressants (R)-fluoxetine, (R)-tomoxetine, (−)-paroxetine, and (R)-duloxetine.

Brine provides remarkable rate acceleration and a higher level of stereoselectivity over organic solvents, due to the hydrophobic hydration effect, in the enantioselective Michael addition reactions of 1,3-dicarbonyls to β-nitroolefins using chiral H-donors as organocatalysts.

Der Cinchona-Sulfonamid-Organokatalysator 1 vermittelt die hoch enantioselektive biomimetische Aldolreaktion von Malonsäure-Halbthioestern mit vielfältigen Aldehyden unter Bildung von optisch aktiven β-Hydroxythioestern. Das Verfahren bewährte sich in Formalsynthesen der Antidepressiva (R)-Fluoxetin, (R)-Tomoxetin, (−)-Paroxetin und (R)-Duloxetin. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and ma

In this study, dithiomalonates (DTMs) were demonstrated to be exceptionally efficient Mannich donors in terms of reactivity and stereoselectivity in cinchona-based-squaramide-catalyzed enantioselective Mannich reactions of diverse imines or α-amidosulfones as imine surrogates. Owing to the superior reactivity of DTMs as compared to conventional malonates, the catalyst loading could be reduced to 0.1 mol % without the erosion of enantioselectivity (up to 99 % ee). Furthermore, by the use of a DTM

Sulfur(VI) fluoride exchange (SuFEx) has emerged as an innovative click chemistry to harness the pivotal connectivity of sulfonyl fluorides. Synthesizing such alkylated S(VI) molecules through a straightforward process is of paramount importance, and their water-compatibility opens the door to a plethora of applications in biorelevant and materials chemistry. Prior aquatic endeavors have primarily focused on delivering catalysts involving ionic mechanisms, studies regarding visible-light photoca

The Mukaiyama aldol reaction is a widely applied carbon-carbon bond forming reaction. However, despite numerous well-established methods using aldehydes as acceptors, only few examples exist with ketones. Here we report a highly practical catalytic approach to this transformation, namely, the triflimide catalyzed Mukaiyama aldol reaction of silyl ketene acetals with ketones. This method exhibits a broad substrate scope, is very rapid, tolerates functionalized substrates, and requires only parts-

Streptomyces spp. are well-known symbiotic microorganisms that produce antimicrobial metabolites against various pathogens. We isolated actinomycetes from the body surface of the termite Odontotermes formosanus and identified it as Streptomyces neopeptinius BYF101 based on 16S rRNA phylogenetic analysis. Chemical analysis of the cultures of termite-associated S. neopeptinius BYF101 via HR-MS 2 and GNPS analyses enabled the isolation and identification of 20 metabolites, including the unreported

Cinchona-based bifunctional catalysts have been extensively employed in the field of organocatalysis due to the incorporation of both hydrogen-bonding acceptors (quinuclidine) and hydrogen-bonding donors (e.g., alcohol, amide, (thio)urea and squaramide) in the molecule, which can simultaneously activate nucleophiles and electrophiles, respectively. Among them, cinchona-derived (thio)urea and squaramide catalysts have shown remarkable application potential by using their bifurcated hydrogen bondi

Carbon dioxide (CO2) is an intrinsically stable molecule. However, its reactivity toward nucleophilic bases has constituted an appealing characteristic for applications such as CO2 capture and functionalization. To shed light on the role of nucleophilic bases in CO2 functionalization, we performed some mechanistic studies using nitrogen-containing bases as an additive—in catalytic amounts—for carboxylation reactions of Grignard reagents. Our kinetic analysis and in situ infrared spectroscopy rev

β-Sulfido sulfonyl fluoride and its derivatives have been gaining attention recently in the fields of medicinal chemistry and material science. The conventional method for the synthesis of functionalized alkyl sulfonyl fluorides requires several chemical transformations. Therefore, a direct establishment of such chemical structures remains challenging, and an efficient catalytic approach is highly desired. Herein a significant "on-water" hydrophobic amplification was achieved, enabling a high-tu

G-, V-, and A-series nerve agents are extremely toxic organophosphorus chemical warfare agents (CWAs) that incorporate P═O functional groups. Their colorless, tasteless, and odorless nature makes rapid and efficient detection challenging. Here, we report an unprecedented N-triflyl phosphoric triamide (<b>N-TPT</b>) receptor, which is a new class of triple hydrogen bonding donor molecular sensors for CWA recognition via noncovalent host-guest-type interactions. The highly robust trifurcate struct

Abstract In this study, dithiomalonates (DTMs) were demonstrated to be exceptionally efficient Mannich donors in terms of reactivity and stereoselectivity in cinchona‐based‐squaramide‐catalyzed enantioselective Mannich reactions of diverse imines or α‐amidosulfones as imine surrogates. Owing to the superior reactivity of DTMs as compared to conventional malonates, the catalyst loading could be reduced to 0.1 mol % without the erosion of enantioselectivity (up to 99 % ee ). Furthermore, by the us